Sunlight driven chemistry at water-air interfaces

Solar radiation is the largest source of energy on both the contemporary and early Earth. An example is discussed involving the robust photochemical mechanism by which α-keto acids, react in aqueous environments to form organic radicals. These organic radicals then drive chemistry leading to larger, more complex lipids. The photochemistry discussed is broadly applicable to all α-keto acids, or oxoacids, as shown by our investigation of species with varying alkyl tail lengths. The generation of such oligomeric organic molecules from smaller precursors is of interest to both current atmospheric chemistry and prebiotic chemistry. The sensitivity of this chemistry to environmental conditions will be examined. Water air interfaces in planetary atmospheres including the contemporary and ancient Earth provide unique chemical environments for the abiotic synthesis of biomolecules. In this presentation, results from our laboratory on condensation reactions possible at the surface of water yet not allowed in aqueous bulk will be presented to discuss the special properties of aqueous interfaces as reaction environments. The examples provided will be cast in the more general framework of the literature discussing the reactivity of interfaces found in natural environments.